—San Francisco-based Apture, whose Web-based system helps publishers keep people around their sites longer by offering pop-up boxes with information related to any highlighted phrase, rolled out a new feature called HotSpots. Apture’s system now learns which phrases users highlight most and makes them into explicit links. “We are trying to track readers who…declare what’s on their mind by highlighting, and turning their behavior into these social links,” CEO Tristan Harris told me.

—In my Friday column I took a look at three recent e-book apps for the iPad that represent some of the best work publishers developers are doing to enhance the reading experience on tablet devices. I reviewed Al Gore’s Our Choice, produced by Melcher Media and Push Pop Press; T.S. Eliot’s The Waste Land, produced by Touch Press and Faber Digital; and Jack Kerouac’s On the Road, produced by Penguin Books and 1K Studios.